findReplaceForm_FormClosed event not occurred

when I close findReplaceFormform, findReplaceForm_FormClosed event not ocurred.
(if close main form, findReplaceForm_FormClosed event occured)
is it normal behavior??)

========================================================
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ActiproSoftware.SyntaxEditor;

namespace actipro_bug
{
public partial class Form1 : Form
{
FindReplaceForm findReplaceForm;
private FindReplaceOptions m_findReplaceOptions = new FindReplaceOptions();
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
// Show the find/replace form
if (findReplaceForm == null)
{
findReplaceForm = new FindReplaceForm(editor, m_findReplaceOptions);
findReplaceForm.FormClosed += new FormClosedEventHandler(findReplaceForm_FormClosed);
}
findReplaceForm.Owner = this;
if (findReplaceForm.Visible)
findReplaceForm.Activate();
else
findReplaceForm.Show();
}

void findReplaceForm_FormClosed(object sender, FormClosedEventArgs e)
{
MessageBox.Show("closed");
//throw new NotImplementedException();
}
}
}

-----------------------------------------------------
sample vs2008 project =>
http://www.orascope.net/question/actipro_bug.zip
-----------------------------------------------------

my pc info
==============
.NET 3.5SP1
ACTIPRO 4.0.0285
XP SP3

sorry for my poor english.

[Modified at 06/30/2010 12:48 PM]

[Modified at 06/30/2010 12:48 PM]

[Modified at 06/30/2010 12:52 PM]